118 Progress 1n Science. |January, 
Physical Geology and Geography.—The Gippsland lakes, as described ina 
Colonial Report by Messrs. A. J. Skene and R. Brough Smyth, occupy extensive 
but shallow depressions in a great extent of level Tertiary country, and have been 
formed by elevation of the land. They are being gradually filled with mud 
and sediment; and every year, with the advance of settlement, the work of 
filling up will proceed more rapidly. 
Professor Archibald Geikie has pointed out facts which lead him to conclude 
that the granite of the Isle of Arran is of Tertiary date. 
The occurrence of erratics at higher levels than the rock masses from which 
they have been derived has been discussed by Mr. James Geikie. He points 
out that stones introduced into the body of a glacier, whether from above or 
below, tend to rise upwards in the ice, as the glacier flows on its way. This fac 
appears to him to solve the question; for a glacier travelling 50 or 100 miles 
may encounter many obstructions in the ground; and, if it surmount these, 
boulders may be extruded at its surface and stranded on the side of some 
rocky hill, many hundred feet or yards above the level from which they origin- 
ally started. 
The origin of the Cheddar Cliffs has been briefly treated of by Mr. H. B. 
Woodward, who advocates their formation by rain and rivers with both 
chemical and mechanical aétion. 
Mr. John Horne, in a sketch of the geology of the Isle of Man, directs 
attention to the glacial beds. The Till (he remarks) is in all respects similar 
to that of Scotland, and is a produé of land ice. There is abundant evidence 
of a strange intermingling of foreign rocks in it, which must have travelled 
from the coast of Cumberland, the south of Scotland, and the west coast of 
Ireland. 
Sub-Wealden Exploration.—This great work progresses slowly and steadily. 
The Oxford clay, last reached, was still present at a depth of ro18 feet. Mr. 
Topley mentions that Ammonites Fason was met with at a depth of gg0 feet. 
There does not appear to be the slightest break between the Kimeridge and 
Oxford clays; the Coral Rag and Calcareous grit being unrepresented, as is 
also the case near Aylesbury, and in Lincolashire and Norfolk. 
Mr. John Gunn has discussed, on several occasions, the probability of 
finding coal in the Eastern Counties, and he has recommended that an experi- 
mental boring be made at Hunstanton. It will be well, however, to await the 
results of the Sub-Wealden Exploration before attempting to prove the 
Paleozoic rocks elsewhere. We learn that at Sperenberg, about twenty-five 
English miles south of Berlin, a boring has been made by the Government 
engineers to the extraordinary depth of 4040 feet. This boring was made, after 
the first 283 feet, in salt-bearing strata; the great depth reached shows us 
what can be done with energy, and with funds! 
Records of Geological Literature.—Mr. Whitaker has done great service to 
Geology by preparing lists of ali papers on Geology, Mineralogy, and Palzon- 
tology, referring to }certain districts. He has published those relating to 
London and Hampshire Basins, to Devonshire, Cambridgeshire, and Witshire. 
It is now proposed to publish, as a yearly volume, a record of all works (in the 
shape of short abstracts) that relate to Geology, whether British or Foreign. 
The first volume will be printed by the middle of 1875, and will contain 
records of papers, books, maps, &c., published during the year 1874. 
PHYSICS. 
LicutT.—M. Craveri has devised a new helio-photometer. It consists of a 
box of hard wood, 280 m.m. long, 145 m.m. wide, and 200 high, forming a paral- 
lelopiped placed upon a pedestal in an open situation, where nothing impedes 
the direé& action of the sun. The upper surface of the apparatus cannot 
preserve, during the twelve months of the year, a horizontal position, because 
when the sun sinks below the equator in winter its rays would fall too ob- 
liquely. It is therefore necessary at that season to follow approximately the 
movement of the sun. This result is obtained by gradually inclining the 
